TY  - SER
AU  - W. E, Krumbein.
TI  - Damage caused by cyanobacteria and fungi in plasters and casting covering medieval frescos in north german rural churches
T2  - News letter 
PY  - 1983///
CY  - Strasbourg-FR : 
PB  - Universite de strasbourg institut de geologia , 
ER  -